Application of the oxidative induction test to depolymerizing systems

Since the development of the oxidative induction time (OIT) test by former Bell Telephone Laboratories researchers, there have been many studies to br oaden its applicability to polymers beyond the original polyolefins. The ba sic premise in OIT studies is that a detectable oxidation onset is based on the differential reactivity between the polymer matrix and free radical sc avenging antioxidants like hindered phenols. This situation does not exist in depolymerizing systems such as polymethylmethacrylates (PMMA), so many r esearchers concluded that a correlation did not exist for these systems. We will report on the observation of a clear cut, Arrhenius-like oxidative in duction time behavior in a toughened PMMA system with high pressure DSC. Th e relationship between the observed OIT at elevated temperatures and high o xygen pressures with lower temperature oven aging studies will be presented . (C) 2001 Elsevier Science B.V. All rights reserved.